'The most dangerous opening a firefighter can make is at the point of entry to a fire involved structure or compartment'.........
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Thread: Tactical Ventilation
02-10-2002, 01:38 PM #1
02-11-2002, 09:54 PM #2
- Join Date
- Apr 2001
With out a charged hose line...
Paul are you giving a test? Your the best.
02-12-2002, 02:42 AM #3
Good on ya Kevin for taking up the 'challenge' - that is a very good point you make....how many times have firefighters initiated their entry point without the protection of a charged line? Sometimes this becomes necessary but....its the control of this entry point that matters.
Can we sometimes consider taking control of our point/s of entry to the fire building?....closing the door behind us?....and closing internal doors behind us?....this is a very controversial topic and should attract opposing views for there are both advantages and disadvantages of such actions.
scenario....'we were advancing our line but the fire was just over-powering the water we had in the stream....in the end we were forced out of the structure as the fire took control....'
another scenario....'as the firefighters removed a ceiling tile a massive air movement into the area took place, followed by an ensuing backdraft as the gases in the ceiling void ignited....'
So by taking control of our entry point (door) we can prevent the much needed air from entering to feed the fire. However - the partial closing of the door ensures the smoke generally will hit the floor until a window is taken out and visibility is greatly reduced. Also, the firefighter's EXIT point is temporarily restricted and a confidence factor ensues.
Is this a good strategy or a bad one?
02-13-2002, 09:45 PM #4
- Join Date
- Apr 2001
Ok Paul now I see were your going. I understand the strategy of
resticting air movement. Its a tactic that has its place and time
but not all the time. Example: Trk. co. arrives no Eng. on scene
occupied tenement, yes leave one guy with a radio to control the
partly closed door to guide the inside team out.The outside team
take there postions ,ladders -firescape - roof rope on roof and prepare to vent and enter when ordered by inside team,good training and self disciplne needed.
Now on the other hand Eng.n Trk. arrive together.Trk. working on door
line is right behind them and being charged,I liked the tactic of
venting bulkhead leave door open let smoke vent Trk n Eng move in
or Eng n Trk depending, with one smooth operation searching
and extinguishing at the same time. Its a beautiful thing.
Of course type of structure , wind conditions,people coming down
stairs from up above will slow down or alter parts of this tactic.
So basically I feel a little bit of this tactic and a little bit of that tactic works depending on the situation. No tactic is Always.
A fire is always changing and you have to be able to adapt and mix
it up when needed. With training and self dicipline and being able
to adapt most times things turn out well..
02-14-2002, 03:52 PM #5
OK Kevin....good points you make. You recognise the potential for delaying the fire's development by controlling the airflow in at the doorway in a situation where truckies enter the structure prior to engine arrival.
Your view then suggests that the smoke should be allowed to vent out of the entry point as the engine advances a line in. You also make the point about protecting escape routes and stairways.
As your smoke vents out of the doorway massive amounts of air may be sucked in below it to feed the fire. You are relying on the fire being located quickly and hoping that the stream they are using will be capable of suppressing the amount of fire that exists within. Its a trade-off....let the fire get bigger at the cost of clearing some smoke and heat out. However, as the fire gets bigger even more smoke and heat is given off!
The advantage of allowing this 'air-track' (air in/smoke out) to progress is that the smoke layer will rise a few inches and visibility may improve near the floor. That air may also be needed by occupants sucking their last breaths! Its still a trade-off.
On occasions it will be better to control that opening and close it a bit to slow the fire.......in other instances it will be better to open it and advance in as you rightly state with the air-track in full swing. What about larger premises? - how many times have firefighters turned up to a large open plan structure - a shopping mall or a warehouse - multiple entry points....large bay door openings wide open....feed that fire!
The point of the post was to make people stop and think because so many times we forget our entry points....we create them to get inside....but then is it better to just leave it or make it part of our firefighting and venting operation? I believe venting a structure is not just about making openings to release smoke and gases but moreso to 'take control' of the openings where possible and in the case of a doorway we can adjust the air-tracks to optimise the conditions to our advantage.
The next time a fire gets away from the stream you are using ask yourself this - did we have control of the air-tracks?
02-17-2002, 01:28 AM #6
- Join Date
- Apr 2001
Paul you suggest in large open structures controlling (closeing)
openings to advance hose line. What I see is a fire that will
be still growing with heat and smoke gasses spreading and banking
down due to the fire load and oxgen present in a large open structure.
Also due to the high ceilings common to these structures if your
timing is not right the possibility of the fire lighting up behind you would increase.I feel the tactic in this situation would be to vent from above the fire if possible to reverse the mushroom affect
of heat and smoke gasses. This way you would be in control of what
the fire will due instead of the fire controling you. I just feel that
the chance of a fire self venting due to heat build up on windows or poor building constuction the fire could suprise and overwhelm the attack line.By timed venting and quick line placement you can make the fire some what predictable .
02-17-2002, 04:51 AM #7
Couldn't agree more Kevin - in terms of vertical ventilation, where possible and where safe. I am also thinking of situations where (a) it is early in the fire and resources are gathering; (b) it is unsafe to go on the roof; (c) it is a situation that is contained within voids or plenums and visible smoke is minor at the outset. These are situations where entry point 'air-track' control could/should be considered.
I think a fire is more likely to travel across the overhead and come down behind firefighters where air-tracks are uncontrolled. We may also address the overhead risk using TICs and pulsing fog patterns as we advance in.
02-17-2002, 04:11 PM #8
- Join Date
- Apr 2001
Still discussing large low rise structures.In situation (A) and (C)
it appears early in the fire and there is not a lot of heat and
smoke gasses being given generated controlling the air feed would be
a good tactic to keep the fire small and contained. I see situation
(B)as a fire in advanced stage with heat and smoke gasses built up,
truss roof,not knowing how long the fire has been burning.
Verticale ventilation would not be safe. Why not use horizontal
ventilation before the line moves in to relieve heat and smoke
(let it blow)to see how the fire will react? Here is a situation.
Daytime fire in a large taxpayer(150x150) were on arrival there is
a medium smoke condition and just with the entrance door open for
the line to be brought in, by the time the line gets towards the rear of the store were the fire area is the smoke mushrooms down to the floor through the store and heat building up the large front windows are now vented conditions inprove and the fire extinguished .
Just trying to make a point that conditions can get bad quickly
with men committed inside a large store. Would'nt it be safer to
vent to help the line make a quick aggressive attack as they enter
the store. Again to bring up the point that properly coordinated
line placement can make the fire somewhat predictable. I understand
slowing down the air movement but a door will have to be chocked open
for the line to make entry. Sometimes thats all a fire needs to start controlling our actions. Question for you Paul as we share info
when you say air-track or air flow do you mean normal air flow or
wind conditions? You British guys got a little different lingo then
us American chaps. Just a little firehouse Humor....
02-18-2002, 05:12 AM #9
Hey Kevin - maybe we can make this the longest two-man thread on the forum .........In the case of the taxpayer either approach may work to your advantage but again - possibly to your disadvantage. The venting of front windows may provide all the air the fire needs to flashover with men committed and on occasions - it may improve visibility and heat to the interior crews advantage. You have to go with the interior crew's information - it should be their call. They should be reading conditions and the situation from where they are and they are the ones who should decide on any venting action.......my view!
Any venting action prior to entry is again down to conditions as they present and of course SOPs. I think that in certain situations you might resign the structure to certain destruction if you vent and invite it 'to blow'......but then in other situations....better to 'blow' before its occupied by firefighters than after!
Again, the point of the post is to put it into firefighters minds that there is another angle to venting Ops - sometimes its better to 'close-down' than 'open-up'?!
'Air-track'.........what scientists term as a gravity current - what firefighters refer to as an inwards air-flow.......same thing
02-19-2002, 04:21 PM #10
- Join Date
- Jun 2001
sorry to break you two up...
In the friendly "vent before and let it blow" or "wait until after entry is made" debate, I gotta go with the do it before camp in 99 out of 100 scenarios.
No argument whatsoever about the control of the fire door, especially when the loss of that control will expose the public hallway in an apartment house or the rest of a large, open floor space in a commercial building. We haven't even addressed high-rise buildings with high wind conditions.
For me, there are a few factors that play into this decision...
1. Do we know where the fire seat is? By letting it blow, I may find out quickly or it may be easier to find out. It also may keep us from unknowingly passing it during our push. I appreciate the concern for flashover with air introduction, but if the heat buildup continues while we are advancing, the storefront windows can go anyway. I'd rather be in a safe spot when they do.
2. Is the building occupied? If there is a possibility of trapped occupants, the decision to "vent for life" is a calculated risk taken to improve conditions in order to prolong their lives and to make it easier for us to drop in and get them without getting beat up too badly. As you said, it is a calculated risk based on, among other things, the location and size of fire, the location of interior partitions and the status of the first line.
3. Structure type? I agree with the assertion that the occupancy type, perceived fire load and life hazard would greatly influence the decision to vent before or after entry. You can get away with things in a 6 story H that you wouldn't try in a taxpayer at 4 AM.
Bravo for the good thread and the lively conversation. I think the brother from 37 Truck and I see things from a similiar perspective. Thankfully, we can get an opinion from someone that was raised in a different way in a different area.
I just thank God that the computer deciphers the accent for us.
02-19-2002, 06:08 PM #11
Welcome to the thread Southbronx brother - Your points are all acknowledged and are based on sound experience. Of course, there are many variations of the 'basic' scenario and you rightly point to airflows that are particular to high-rise situations as another consideration.
Here is a view and I might be wrong - but I believe most venting actions occur AFTER the structure has become occupied by firefighters? I am very interested to hear about your experiences in 'H' Block apartment buildings (thought they had all burned down in the 70s!!). What considerations are specific to H Blocks in terms of venting actions? I do remember these buildings suffered rapid fire spread due to their geometrical layout and lack of fire stopping.
I do know you guys like to 'open-up' in the bronx and I agree there is most certainly situations that benefit. I must say that FDNY and also Chicago FD are extremely aggressive in their venting actions and shirk at nothing in their efforts to release the gases.
There was a fire in 1998 in a Swedish dance hall that killed over 60 youngsters at a Halloween ball. The fire was modelled by scientific computer analysis (CFD) and it demonstrated that heavy smoke was creating problems where it was forced out of the main entrance doorway. On venting the windows along the side of the dance-hall the flows reversed at this doorway with air creating a clear path into the rear of the hall. However, the fire increased dramatically in intensity with flames issuing from all windows. In that situation the conditions would have suited firefighters advancing lines into the main doorway and it was believed that all deaths had occurred prior to this point.
Don't get me wrong on this point - I am a strong believer of tactical venting actions - but also a believer that in some situations we need to observe exactly what the airflows WE have created are doing to the fire - is it a positive or a negative effect? We might then want to think about controlling these effects.
Acccccccccent You're the ones with an acccccccccccccccceeeeeeent!!!
02-20-2002, 01:06 AM #12
Pardon me for sticking my nose in...
I understand the concpet that you are trying to get across Paul. But I also believe what the esteemed gentlemen from FDNY are saying is also very true.
Controlling the door to the fire compartment is essential. It can/will limit the spread of smoke and flames. But closing doors as you make your way through the structure?? I think that would most definetly have to be on a case by case basis.
As Kevin from 37 Truck mentioned, when the Engine and Ladder operate in concert with one another - it's a beautiful thing.
I feel - and I am sure that you gentlemen will correct me if I am wrong - but more work/training could be researched at controlling fire spread through aggresive ventilation - both vertical and horizontal.
I have seen many a FD 'battle' a fire because their own ventilation tactics have pushed the fire at the handline....
"In Omnia Paratus"
Member - IACOJ
-- The opinions presented here are my own; and are not those of any organization that I belong to, or work for.
02-20-2002, 01:06 AM #13
- Join Date
- Apr 2001
Im still in this. Paul the problem with top floor fires in
H-Type buildings was your raised roof sitting on a large
open cockloft.I will try to build it up for you. the top
floor ceiling is attached to the roof joist typically in
those buildings a true 2x8 to 2x12 large lumber 16 inch.
on center. Then on top of the joist the roof is gradually
pitched, built up with 2x4 for drainage, low point being around center of roof.
High point working its way towards the throat
as much as 2ft.in height. Next your tongue and groove boards then
maybe 3 layers of roofing. Basicly the cockloft has a heavy
wood fireload. Our tactic was to cut a hole over the fire
usually 6x6 pull, push ceilings down to create a up draft
for heat and smoke to excape. If the fire is in the cockloft
you want to increase the size of the hole to slow down the
horizontal fire spread. With this you have a few lines working
underneath with a few hooks pulling ceilings, more the better.
This tactic will usually keep fire from crossing throat into
the adjoining wing. But if you have a junkyard fire apartment
with rubbish piled up to the ceilings, wind condition pushing
the fire through cockloft or fire was started by an accelerant
and advanced before your arrival you would add the trench cut
in the narrow part of the throat to keep fire from extending
to adjoining wing. Trench cut 3ft.wide , width of throat pulled
with line underneath and line on roof. Line on roof is not your
primary trench line. This tactic worked well most of the time
but due to some of the problems I mentioned above sometimes
it gets ahead of you and its time for the tower ladders.
For highrise that So.BX brought up, good topic to add to this
post. My experence has been residental type. When your going
in with the wind pushing the fire down the hall. Your Not.
Even with 2 lines working and a bunch of spare engine men,
untill the wind shifts or the contents (fuel) burns off.
Paul the windows were not vented by FF. Jump in on this one
02-20-2002, 11:15 AM #14
Boy do I remember those ****-loft fires Kevin Are there many H buildings left in New York? I remember each borough had its own particular type of structure common to that area and each type brought specific problems and required a variation in venting tactics. Your description of cockloft construction certainly brought back some memories of long cold nights!
As I've said before on the forum - the air-flows through high-rise structures can be influenced by wind (as you say) and also stack effects. I think the phenomena related to stack flows is frequently misunderstood or forgotten by firefighters. If EVER there was a good time to CONTROL & MINIMISE your door entry points its in high-rise fires.
Hey there Marc - Your points are worthy of note - 'As Kevin from 37 Truck mentioned, when the Engine and Ladder operate in concert with one another - it's a beautiful thing'.....Here in the UK we have so much to learn from this approach to firefighting. In 1984 I personally initiated a gradual transition in the UK towards a greater awareness of tactical venting actions and such coordination in the attack. We are still not there yet although we now have ventilation manuals!
'I feel - and I am sure that you gentlemen will correct me if I am wrong - but more work/training could be researched at controlling fire spread through aggressive ventilation - both vertical and horizontal'.....Marc, that objective is now closely be researched by the USFA and information may be seen at http://www.usfa.fema.gov/research/nist.htm
'I have seen many a FD 'battle' a fire because their own ventilation tactics have pushed the fire at the handline'....That is SO true mate!
As Kevin says - jump in here guys on any points of view.
02-20-2002, 12:47 PM #15
- Join Date
- Jun 2001
It is a testament to the fraternity of the fire service that an Englishman can say "H-block" to an Irish Catholic and not start a riot. If Bobby Sands could see us now.
The Bronx is loaded with 6 story H-types, as far as the eye can see. Alot are vacant, but many are still thriving after renovation (good economy and all). I think the far south, (like 60/17, 83/29) probably have the most lingering damage from those days. The northern part of the 6th division and most of the 7th still do a fair amount of work in these buildings.
Kevin hit the main problem with H's (aka New Law Tenements), controlling the cockloft. Some interior partitions are of masonry in the newer types, which can slow lateral spread within the units, but the walls stop at the top floor ceiling. This leaves the cockloft wide open, and as Kevin stated, loaded with lumber. The open public hallway and wood walls and floors create tremendous potential for fire spread throughout.
The other thing for us is the varied floor plans of these apartments. In Old Laws, we can move through the "railroad flats" with our eyes closed. Many NLT's have unique lay-outs that require some studying. Stairwells are also varied in type and location; wing stairs, transverse, etc.
As for the ventilation priorities, the bulkhead at the roof level is first and foremost. This will clear the public stair and hall for egress and allow for easier access for the inside team and engine co.. Nothing shall deter the roofman from this position or duty... nothing. As soon as the position is reached, the door is gone, irrespective of the status of interior operations.
At top floor jobs, the roof will get a hole directly over the fire ASAP, or the scenario Kevin described will soon follow. The first and second due roof usually hook up, the OV may help out if he cant get in on the fire floor and sometimes you can even get a guy from Rescue to help out. But if you are too late, for whatever reason, the trench cuts and tower ladders are not far behind.
As for the fire apartment or room, the OV will vent that area from the fire escape (or portable) in a position opposite of the advancing nozzle. He will then drop into the other rooms of the apartment for VES. The timing of this vent depends on "for life" or "for fire". If "for life", it will be performed immediately, so as to facilitate the search for known victims. If "for fire", he will wait until the line is stretched and in a position to control the fire.
I guess the answer to your question about venting before members are in the building comes down to a timing issue, based on many factors. If the roof man gets to the bulkhead before the inside team gets in the building, the door is going. However, the OV will usually wait until the engine is in position, or he is ordered to vent by the truck officer... unless there are suspected victims.
Of course you know that special situations in sealed taxpayers or warehouses, early in the morning, require vertical vent to take place before any entry is made at ground level, but this usually does not apply to apartment buildings.
Kevin... fill in the blanks for me. I know you saw your share up on Briggs Ave in the heavy days.
Once again, its good to talk with you about these issues. Its a good drill for us all. Accent? You never knew how bad you guys butcher English over there... until you spent some time in the Bronx.
Last edited by southbronx; 02-20-2002 at 12:54 PM.
02-20-2002, 01:08 PM #16
It is a testament to the fraternity of the fire service that an Englishman can say "H-block" to an Irish Catholic and not start a riot. If Bobby Sands could see us now'.....
02-20-2002, 01:24 PM #17
'He will then drop into the other rooms of the apartment for VES. The timing of this vent depends on "for life" or "for fire". If "for life", it will be performed immediately, so as to facilitate the search for known victims. If "for fire", he will wait until the line is stretched and in a position to control the fire'.....
That venting action 'for life' interests me greatly. There MUST be occasions where that strategy worsens conditions for trapped occupants? Is it a gamble based on a calculable risk, that in turn is based on experience? ie; is it a strategy that works on a much larger percentage (of occasions)? Is it quantifiable....ie; can we honestly say when the strategy worked for us? It will be obvious when it didn't.
Also... 'special situations in sealed taxpayers or warehouses, early in the morning, require vertical vent to take place before any entry is made at ground level'....
Is that FDNY's SOP or just accepted good practice? Is it rigidly followed in NY? Is that practice followed elsewhere in US? Anyone jump on this....
Thanx for your input brothers.........it is truly educational and I am sure we are all learning from this thread.
02-20-2002, 05:10 PM #18
- Join Date
- Apr 2000
If nobody minds, I thought I might throw something in for consideration- In the Worecester tragedy, the vertical ventilation on the roof and the entry into the building through garage-type doors on the ground helped turn the structure into a 6-story brick oven, with the (vented) elevator shaft acting as a chimney, drawing air through the doors and up into the fire. Probably unforseeable at the time, but something to consider for the future maybe?
Disclaimer- NONE of that was an attempt at second-guessing. Just wondering about thoughts of others on the subject.
02-20-2002, 05:24 PM #19
- Join Date
- Jun 2001
The OV position is definately a spot for a thinking man. Not only does he have to know building layout and construction features in order to position himself quickly and correctly, but he must make many decisions on his on, based upon his experience and the conditions he sees.
As for venting horizontally "for life", this decision, as you asserted, is absolutely a calculated gamble. But the knowledge of a few key pieces of information can help make the decision.
Most important is the fire and victim location. In a tenement (old or new), the OV generally positions himself on the front or rear fire escape, opposite of the nozzle, in a spot that will allow him to VES the fire room or apartment.
As a rule, a single fire escape serves two seperate apartments, or two rooms in the same apartment. Knowledge of specific building layout, reading of visible fire conditions, and/or an educated estimation of the interior configuration will tell the OV where to vent and where to enter.
If the location of the fire is known, the OV can now guess as to the effect of his vent on it. If it is close to the window or in a bedroom served by that window, venting will probably help the conditions in the rest of the apartment. If the fire location is not clear, venting may draw the fire from a living room or kitchen into the bedrooms.
If the victim is known to be in a specific room or rooms the decision becomes easier, because the effect of ventilation on that location can be evaluated, as opposed to evaluating the entire apartment. By quickly checking the conditions in each window, the OV can decide where to vent and where to enter.
If the victim is in a room that obviously has fire in it, venting is almost certainly going to improve it for him, and will allow the OV to drop in quickly and get out. If fire blows out upon venting, the best he can hope for is to probe the floor under the sill and then find another window.
I believe that in most cases, (could be wrong), if the fire is going to react explosively to venting, the conditions in the room are probably already untenable. The big concern, though, would be drawing it from another area into the spot we need to get to.
One key to remember is that the OV has to get into the apartment to search. If the fire is blocking the inside team, he may be the only one that can reach the victim prior to water being applied.
What he is really doing is either trying to open a window away from the victim and himself, in order to draw the fire away from them and generally improve conditions or he could be letting the fire go out a window that it is close to, in order to keep it from spreading through the interior of the apartment.
It may not be desirable to enter the only vent the fire has, so opening a window other than the one you will enter is almost always desirable.
Can we honestly say when it works? Sure... like when the inside team was taking a real beating during a search and suddenly the condition lifts enough for them to make the back rooms. Its important to remember that although we are trying to improve conditions for the victim, we are also trying to make it easier for us to find them.
Is it a gamble... absolutely. Anytime you vent horizontally without the line in position, you are rolling the dice. But with a heads-up brother on the OV, you can make an impossible situation tenable.
I know that is a lot of disjointed rambling and I probably didn't say all that I wanted to, but its tough to convey it here. As you know, we in The Bronx have to wave our arms and curse alot to get a point across. Hopefully, you can get the main idea.
PS... As far as Taxpayers in he middle of the night, when we get there and its not coming out the windows, the bosses talk to each other immediately about getting to the roof. SOP? Not in stone that you always do it, but the brothers all know what to look for and where they will see it. Because you dont know how long the fire is burning and you do know that the owner has sewed the place up tight, you have to assume that a backdraft could definately be in the cards.
In addition to backdraft, be ready for occupants that were locked behind the rolldowns for the night.
Last edited by southbronx; 02-20-2002 at 05:34 PM.
02-20-2002, 06:07 PM #20
Sth/Brnx - Your 'disjointed rambling' has resulted in a truly excellent post - one of the best I have seen on the forums.
Your point that the OV person must have a high level of awareness and in-depth knowledge of the structure layout is essential. I can relate to exactly what you are saying here and your views are supported by documented scientific and practical research that has analysed the effects of venting a window in the fire compartment (generally good) as opposed to venting one in an adjacent compartment (generally bad) - not cast in stone!.
You make it clear that venting can 'draw' and worsen the fire in some situations and yet if the fire is 'drawn' away from potential victims then of course, this can be a very good thing!
I think you have demonstrated that tactical venting actions CAN be and ARE used to great effect where 1) The structure is known; 2) The OV person is experienced in this role; 3) A good size-up is made before venting; and 4) The roll of the dice is 'lucky' for us! If points 1-3 are assured then its most likely the dice WILL be kind to us....If the structure does not have the fire escape then the size-up and application of any OV action is severely hindered.
Great post -
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